[stripes1776]

Clean your fan and cooling heat sink with canned compressed air. Sometimes they have to be taken apart which if you don't know what you are doing and have the proper dis-assembly guide, you can really screw a laptop up. But canned air does a good job and usually fixes the issue.

I have never had a Dell laptop overheat, but I do see where the dust could be a problem. I will give it a try. But perhaps all the "vent" holes on the back of the HP would allow dust to accumulate faster.

[Cold Heat]

All laptops have a cooling fan and most if not all have the intake somewhere on the bottom of the chassis with out vents on the back or sides.

First unplug it and shut it down, blow air backwards though the out vents to loosen up the crude, then blow through the inlet to blow it out or it will get lodged in the inlet screen. Repeat as necessary until you don't see stuff blowing out. But don't over do it or you could damage the fan blade, but that has never happened to me.

Canned air does not have enough pressure, but a air compressor would likely hurt it if blown too hard, which is why I suggested the canned air.